The New York Times is reporting that James A. Johnson, the consummate Washington insider whom Senator Barack Obamaa tapped to head his vice-presidential search effort, resigned abruptly on Wednesday to try to silence a growing furor over his business activities.

Johnson’s departure deprives Mr. Obama of decades of experience and access to Washington’s power elite. Johnson has been a fixture in Washington political and legal circles for three decades, and he led the vice-presidential search team for Senator John Kerry, the Democrats’ presidential nominee in 2004, according to the New York Times.

Obama said Wednesday afternoon that “Jim did not want to distract in any way from the very important task of gathering information about my vice-presidential nominee, so he has made a decision to step aside that I accept.”

And the national campaign has officially begun.